dom4j解决Premature end of file

使用dom4j解析来自InputStream中的XML内容，发生异常：Premature end of file

原来是这个InputStream已经读过了，在读入dom4j时，不是从开头读的，因此报错。

详细解释如下：来自http://forums.sun.com/thread.jspa?threadID=641465

Problem: Input stream is opened and read bytes from it, passed the same to document builder to parse method. so it caused the exception saying premature end of file.

Solution: Pass fresh input stream which is opened and not read anything (bytes) before passing to parse method of DocumentBuilder object.